Yes, I've heard of those 1992 Topps Round Trippers before and have even seen pictures of the Kirby Puckett front with blank back and The Kirby Puckett back with blank front. The pics I saw were taken several years ago and I've been searching for the Puckett's for my personal collection.
I didn't realize his were also blank front and back. I agree though with Jeremy that these are legit. We both know the person that already owned these and the ones listed match his. Just makes me wonder how many are actually out there.